College as a Marriage Market

What explains the strong educational homogamy and assortativity that we observe among the college educated? We use Norwegian data to address identification and measurement challenges and find that colleges are local marriage markets that matter greatly for whom one marries, not because of the pre-determined traits of the admitted students but as a direct result of attending a particular institution at a given time. The effects of enrollment on homogamy that we uncover are sufficiently large to explain the majority of the strong educational sorting among the college educated in our data. We also examine the mechanisms behind these effects and explore implications for individual and family earnings.